CONTENT BIO 3

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DEFINE ETIOLATION

WHEN PLANTS DON'T GET ENOUGH LIGHT. THIS STIMULATES STEM GROWTH OR STEM ELONGATION.

NIACIN FUNCTIONS IN MAINTAINING WHAT?

NORMAL NERVE FUNCTIONS.

Niacin is usually thought of as the vitamin that prevents pellagra. Persons consuming insufficient niacin may also develop disorders of the digestive system, skin, and the nervous system.

Fats, like carbohydrates are composed of carbon, hydrogen, and oxygen, but differ from them by having.

proportionally less oxygen

In fats, the ratio of hydrogen atoms to oxygen atoms is much higher than 2:1.

The loss of water by transpiration is the result of---------.

diffusion.

Transpiration is the evaporation of water from the aerial part of plants. Evaporation is a result of the molecular activity called diffusion.

The "dark" reactions of photosynthesis take place WHERE?

stroma.

The dark reactions of photosynthesis use the energy of the ATP, which is formed in the light, for their essential processes, all of which take place in the clear stroma, which surround the grana of the chloroplast.

WHAT IS THE PHOTOSYNTHESIS FORMULA?

6CO2 + 6H2 + Radiant Energy -> C6H12O4 + 6O2

In the "dark reactions" of photosynthesis, WHAT OCCURS?

ORGANIC SYNTHESIS OCCURS.

The dark reactions of photosynthesis include the reduction of carbon dioxide and its combination into 3- and -6-carbon sugars. This is followed by a series of reactions in which the sugar ribulose is replaced.

YOU WANT TO COPY A SINGLE GENE OR PIECE OF DNA. WHAT DO YOU USE?

POLYMERASE CHAIN REACTION...PCR

DEFINE RFLP

RESTRICTION FRAGMENT LENGTH POLYMORPHISM

WHAT IS A DISPLACEMENT REACTION?

Replacement (displacement) reaction is one where compound breaks apart and forms a new compound plus a free reactant.

AB + C →AC + B or AB + CD → AD + CB.

The breakdown of a disaccharide releases energy which is stored as ATP. This is an example of a(n)
A. Thermodynamic reaction
B. Endothermic reactionC. Exothermic reaction
D. Replacement reaction
E. Combination reaction

C. Exothermic reaction

(this multiple choice question has been scrambled)

Which of the following molecules is thought to have acted as the first enzyme in early life on earth?
a. Protein
b. RNA
c. DNA
d. Triglycerides
e. Phospholipids

B: Some RNA molecules in extant organisms have enzymatic activity; for example the formation of peptide bonds on ribosomes is catalyzed by an RNA molecule. This and other information has led scientists to believe that the most likely molecules to first demonstrate enzymatic activity were RNA molecules.

All but which of the following processes are ways of moving solutes across a plasma membrane?
a. Osmosis
b. Passive transport
c. Active transport
d. Facilitated diffusion
e. Endocytosi

A: Osmosis is the movement of water molecules (not solutes) across a semi-permeable membrane.

Which of the following cell types has a peptidoglycan cell wall?
a. Algae
b. Bacteria
c. Fungi
d. Land plants
e. Protists

B: Bacteria and cyanobacteria have cell walls constructed from peptidoglycans – a polysaccharide and protein molecule. Other types of organisms with cell walls, for instance, plants and fungi, have cell walls composed of different polysaccharides. Plant cell walls are composed of cellulose, and fungal cell walls are composed of chitin.

Enzymes catalyze biochemical reactions by
a. Lowering the potential energy of the products
b. Separating inhibitors from products
c. Forming a complex with the products
d. Lowering the activation energy of the reaction
e. Providing energy to the reaction

. D: Enzymes act as catalysts for biochemical reactions. A catalyst is not consumed in a reaction, but, rather, lowers the activation energy for that reaction. The potential energy of the substrate and the product remain the same, but the activation energy—the energy needed to make the reaction progress—can be lowered with the help of an enzyme.

T OR F
Enzymes are substrate-specific. Most enzymes catalyze only one biochemical reaction

TRUE

DEFINE synaptonemal complex

the point of contact between homologous chromatids. It is formed when nonsister chromatids exchange genetic material through crossing over. Once meiosis I has completed, crossovers have resolved and the synaptonemal complex no longer exists. Rather, sister chromatids are held together at their centromeres prior to separation in anaphase II.

DEFINE TELOMERASE

It adds a repetitive DNA sequence to the end of chromosomes.

Each time a cell divides; a few base pairs of DNA at the end of each chromosome are lost.

Telomerase is an enzyme that uses a built-in template to add a short sequence of DNA over and over at the end of chromosomes—a sort of protective “cap”. This prevents the loss of genetic material with each round of DNA replication.

WHAT IS Topoisomerases ?

Topoisomerases are enzymes that regulate the overwinding or underwinding of DNA. The winding problem of DNA arises due to the intertwined nature of its double-helical structure.

TOP 1 DOES ONLY 1 COIL

TOP 2 DOES 2 AT A TIME.

SEEN DURING DNA REPLICATION WHEN THE HELIX IS SPLIT AND TENSION OCCURS DOWN THE LINE.

LAC OPERON

IN PROKARYOTIC.

4 PARTS

PROMOTER. WHERE RNA POLYMERASE GRABS

OPERATOR. ON/OFF SWITCH

REPRESSOR. LOCK. LACTOSE IS THE KEY.

GENES ON DNA

LACTOSE GETS INTO SYSTEM.

ACTIVE SITE OF REPRESSOR GETS FILLED WITH LACTOSE.

RELEASES IT FROM OPERATOR.

RNA PLOYMERASE LATCHES ONTO THE PROMOTER AND RUNS DOWN THE DNA AND MAKES ENZYMES (PROTEINS) THAT BREAK DOWN LACTOSE.

STOPS WHEN LACTOSE NOT PRESENT IN SYSTEM. (FEEDBACK LOOP)

T OR F
DNA polymerase does not match base pairs with 100% fidelity

TRUE.

Some level of mismatching is present for all DNA polymerases, and this is a source of mutation in nature. Cells have mechanisms of correcting base pair mismatches, but they do not fix all of them.

Which of the following mutations is most likely to have a dramatic effect on the sequence of a protein?
a. A point mutation
b. A missense mutation
c. A deletion
d. A silent mutation
e. A proofreading mutation

C: Insertions and deletions cause frameshift mutations. These mutations cause all subsequent nucleotides to be displaced by one position, and thereby cause all the amino acids to be different than they would have been if the mutation had not occurred.

A virus that has incorporated into the DNA of its host.

PROVIRUS.

In the lysogenic cycle, viral DNA gets incorporated into the DNA of the host VIA BACTERIAPHAGE.

A virus in this dormant stage is called a provirus.

Eventually, an external cue may trigger the virus to excise itself and begin the lytic cycle. WHERE IT BREAKS FREE DESTROYS CELL DNA AND CELL MAKES VIRUS DNA.

A virus in this stage is actively replicating DNA

IN the lytic cycle, viruses use host resources to produce viral DNA and proteins in order to create new viruses. They destroy the host cell in the process by lysing it. For this reason, actively replicating viruses are said to be in the lytic cycle.

THE FIRST PART IS THE LYSOGENIC CYCLE, WHEN BACTERIAPHAGE INJECTS ITS DNA AND IS INCORPORATED INTO THE CELLS DNA. BUT IT DO NOT REPRODUCE IT. THAT IS THE LYTIC STAGE.( WHEN IT BECOMES ACTIVE)